| 摘要 |
PURPOSE:To reduce distortion occurring in a joint between frames at the time of compressing or expanding by providing a power calculation part calculating power at each frame and eliminating or inserting the frame with lowest power among several pieces of frames according to a compression and expansion ratio. CONSTITUTION:An input sound is divided into prescribed frames by a frame divider part 1, and the divided sound is inputted to a power calculation part 5 and a frame insertion/elimination part 2. In the power calculation part 5, power at each frame in the inputted sound signal is calculated, and a value obtained as a result is outputted to the frame insertion/elimination part 2. Then, in the frame insertion/elimination part 2, several pieces of frames are put together under the control of an compression/expansion adjustment part 4 according to the compression or the expansion ratio required, and the frame with lowest power among them is eliminated or inserted. For example, when the sound signal is compressed to 2/3, three frames are put together, and the frame with lowest power among them is eliminated. |
